Apparatus for making salt



April 1942- c. s. RQBISON 2,279,061

APPARATUS FOR MAKING SALT Filed Oct. 23, 1939 2 Sheets-Sheet l ATTORNEYS QQLQ W2 Q Q H4 5 i Q h? N w Wm s Q) 5 INVENTOR. (RN BY 566/2502 L5. fiafizlso/z M /mm/J'w April 7, 1942. c. s. ROBISON 2,279,061

APPARATUS FOR MAKINGjAL T Filed Oct. 23, 1939 2 Sheets-Sheet 2 INVENTOR.

ATTORNEYS Patented Apr. 7, 1942 UNITED STATES PATENT OFFICE APPARATUS FOR MAKING SALT Clinton S. Robison, Chicago,'Ill.

Application October 23, 1939, Serial No. 300,806

4 Claims.

My invention relates to apparatus for making salt.

This inventionis directed to apparatus of the character referred to particularly suitable for open pan work, which assures large area of surface contact. of the brine with the surrounding medium or air, while also assuring a high rate of movement of the brine in contact with the air and avoiding necessity of using paddles, rakes and analogous mechanical agitators; all to the end of rapid evaporation and the production of clean and unbroken salt crystals of high grade and desired type. More specifically, I provide a grainer of improved construction having a shallow top portion in which a body of brine, presenting a considerable area of contact with the surrounding medium or air, is agitated and rotated by a stream of brine, the salt crystals as formed being deposited in an intermediate portion of the grainer depending from the top portion and of materially less cross sectional extent at its upper end than the top portion, the intermediate portion having a depending leg which receives the slurry. Further objects and advantages of my invention will appear from the detail description.

In the accompanying drawings, in which is shown the preferred embodiment of my invention:

Figure 1 is a fiow diagram of the apparatus embodying the grainer of the present invention;

Figure 2 is a plan view of the grainer pan of Figure 1;

Figure 3 is a fragmentary elevational view, on an enlarged scale, of the grainer pan leg or column shown in Figure 1;

Figure 4 is a vertical cross sectional view through a union of a jet brine line leading into a slurry'discharge pipe, and showing embodied therein a disc having a fixed orifice, this view being taken along the line 4--4 of Figure 3; and

Figure 5 is a vertical sectional view through a heat exchanger suitable for use with the grainer of the present invention.

Referring now in detail to the drawings, it will be seen that the present invention employs a heat exchanger 8 and a grainer 9. The heat exchanger 8 comprises the drum ll, closed at its opposite ends by the cover plates I2l3 and separated into upper and lower chambers |4-l5, respectively, by the header drum I6. This latter drum is provided with a central axial well I1, andtubes I8 surrounding such well are extended between the upper and lower header plates l9- 2l; respectively, to which they are secured in a known manner. Chamber I4 is provided with the diametrically opposed outlet openings 22 and 23, while chamber I5 is provided with the axial inlet opening 24. Diametrically opposed inlet openings 25-26 are also provided for drum l0. Propeller 21, disposed in chamber I5, is carried on one end of a shaft 28 extending axially through well ll and through a, bearing 29 carried by a tripod 3| which is disposed in chamber l4 and suitably secured to header H9 in any preferred manner. From bearing 29, shaft 23 extends through a suitable stufiing box 32, embodled. in cover plate l2, and has connection to an electric motor 33 carried by a suitable support 34, this support being secured to cover l2 in any preferred manner. Vent pipe 35 communicates with the upper portion of drum it, while condensate pipe 36 communicates with the lower portion of drum l0.

The evaporator or grainer 9, which may be formed of any suitable or preferred material, comprises a pan 31 of appreciable diameter but relatively shallow depth, and having an opening 38 in the wall 37a thereof that opens into the pan substantially tangentially to the inner surface of the wall. The purpose of this opening 38 will hereinafter appear. Centrally, the pan is provided with the opening 39 which provides communication to the interior of a frusto-conical shaped portion 4| depending from the pan. A tubular leg 42 depends from the apex of portion 4| and is provided with a pair of vertically spaced upper and lower observation windows 43 and 44, respectively. The lower end of leg 42 is also of frusto-conical shape for connection to a sectional standpipe 45, which comprises the grainer shut-off valve 46, the lump line connection 41, the grainer emptying and filling line 48 and shut-01f valve 49, and the sewer outlet valve Horizontally spaced-apart slurry discharge pipes 52-53 communicate with the interior of leg 42 through the frusto-conical portion thereof. Such pipes are provided with the shut-off valves 54. Nozzles 56 on the pipes 54 discharge into the hoppers 58 and 59.

Figure 1 illustrates the arrangement of the grainer and heat exchanger, together with other knownapparatus to meet the requirements of the instant process. A brine storage tank 6| is connected by pipe 62 with the emptying and filling pipe 48 of the grainer. A pipe 63 also leads from tank 6| to a brine feed pump 64. From the discharge of this pump a, pipe 65 leads to leg 42 of the grainer, and a brine jet pipe 66 of relatively small diameter leads from pipe 65 t0 the slurry discharge pipes 52, 53. A pipe 61 also leads from pipe 65 to apipe 68 connected between the frusto-conical portion of grainer 9 and the inlet of a circulating pump 69. The discharge of pump 69 is connected with inlet opening 24 of heat exchanger 8 by a pipe 1|, and from this latter pipe a pipe 12 leads to tangential opening 38 in the grainer pan. Outlets 22 and 23 of heat exchanger 8 are connected by pipes 73 and 14 with a flasher 15 of known construction, this flasher having a vapor outlet 16 and a submerged outlet 71 that delivers preheated brine to the grainer. V

In operation, the entire system is first filled with brine to be evaporated. The brine circulating pump 69 is then started, which causes the brine to be continuouslycirculated from" grainer 9 to heat exchanger 8, thence toilasher l5 and back to the grainer, a certain amount of heat and steam passing to atmosphere from the flasher 15 through the vapor outlet 16. Any required number of heat exchangers may be employed, and any desired steam pressure can be applied thereto. The steam enters openings 2526 and passes aroundthe tubes i8, while the brine enters inlet opening 24 and passes through the tubes. Circulation of the brine by pump 69 is augmented by the power .circulator or motor driven propeller 21, which draws brine down through the centralwell l1 and up through the tubes 18 at a, high velocity rate which-accomplishes a rapid heat transfer and, at the same time, by reason of thehigh velocity, the formation of scale on the heat transferences, or tubes, has been found to be eliminated. Brine inthe grainer is, by this heating process, gradually brought up to the desired temperature. The temperature range of evaporation for the production of various grades of salt will be between 170 to 210 F. 'I'hehigher the temperature the finer will be the salt crystal aggregates.

It is known that the rate of evaporation is increased proportionally with the movement of the fluid that is being evaporated and the air that is in contact with the fluid under process of evaporation. Movement of the .fiuid being evaporated has a further advantage in that it prevents a crust forming on the surface of the fluid, a condition which retards evaporation and further results in the development of what are termed mushy crystal aggregates, a type of crystal which is unsuitable for trade requirements. To secure movement of the fluid, to the end stated, it has heretofore been the practice to employ mechanical means, such as mechanical agitators, rakes, paddles, and the like, which have been and are a continual source of costly maintenance and operation. These mechanical devices are furtherobjectionable by reason of the fact that they have an action of crushing up the crystal aggregates of salt and contaminating the product, incrustants that form on their surfaces being continuously dislodgedand particles thereof remaining in the product.

In the present invention it will be observed that the above problems have beensolved by the provision of pipe 12 extended between pipe H and the tangential opening 38 in grainer 8. As the system is filled'with brine, the circulation of the brine through the system by .pump 69 will cause a certain amount of the brine to be forced up pipe 12 into grainer 9. This creates a circumferential circulation of the brine in the grainer. As soon as the brine inthe system reaches full saturation, crystals of salt will form on the surface of the brine in the grainer and, as formed, will be moved to the center of the grainer and into leg 42 by centrifugal action. This circumferential movement of the brine in the grainer, by the tangential injection of brine thereinto, causes uniform development of crystal aggregates over the entire surface of the brine and at an increased rate over the conventional type of grainer, where the brine is practically in a state of suspension. It also avoids breaking or crushing of thesalt crystals, such as is caused by the mechanical devices above referred to, thereby assuring a better product. Formation of salt on the grainer pan walls is also eliminated.

As the slurry or salt crystals settle into the leg or launder column 42, they are washed or laundered by brine fed to the leg through pipe 65 by the brine feed pump 64. This brine replaces the brine lost from the system by evaporation, etc., and also washes the crystals of their mother liquor as well as freeing them of impurities which tendto become concentrated inthe leg, thus assuring a purer product.

-No slurry or salt is withdrawn from the leg/l2 until .it is observed in the top observation glass 43, at which time proper nozzles 56 are lined to the discharge pipes 52-53. Valves. 54 .are then thrown wide open and the slurry iSlSJlUWQd to discharge into the hoppers 58 and 5!. flme rate of slurry discharge is determined by the size of the .nozzle'orifices. .A plurality of removable and replaceable nozzles '56 having diifereut diameter orifices are provided .and employed :in suitable combinations to suit the conditions of slurry discharge from the system. Use of two nozzles is also advantageous, as by using one-or the other alone the desired height of in the leg can readily be maintained, especially where the two nozzles have different :sizes of orifice.

As the slurry passes through the slurry discharge pipes 52-43, brine is delivered thereto by the brine feed pump 6'4 through the brine giet pipe 66. .As shown in Figure 4, the 11111011 .18 in this pipe is provided with 'a disc 19 having a fixed orifice 8|. The size of this orifice 31 is such as to permit only a proper amount of brine to :be admitted to pipes '5253 to keep thefslumy sufliciently fluid to assure flow through nozzles 56'at proper rate, as before explained, with valves 54 fully open.

From hoppers 58-59 a pipe '82 conducts the slurry to a slurry pump 83 which, in turn, fipa'sses theslurry through a pipe 84 to a torpedo washer 85,.this washer having an foverflow pipe :86 communicating with tank 61.. 7' From the washer '85, the slurry is delivered to a feed tank I81 and thence to a filter 88, which delivers the :drysalt to a conveyor 89, the .brine being delivered to tank '61 in any suitable or preferred manner. The :washer, lfeed tank, filter and conveyor are of'known types and need not be explained .here in detail.

While a preferreduemb'odiment I01 my invention has been illustrated and described, '--by way of example, it will be obvious that changes may be made therein within :the spirit and scope or the invention "and, therefore, the invention is not limited to the precise 'form herein described, except in so far. as it may be so limited *by the appended claims.

1. A 'grainer'cf the class described comprising a "shallow cylindrical top portion having an opening-in the side wall thereof through which brine may be injected tangentially into said top portion, an inverted frusto-conical intermediate portion depending from said top portion concentric therewith, the upper base of said intermediate portion being of materially less diameter than said top portion, and a leg depending from the lower base of said intermediate portion.

2. A grainer of the class described comprising a substantially cylindrical shallow top portion,

said top portion in a direction to agitate and impart a rotary motion to the body of brine therein, therebyto secure maximum exposure of the brine in said top portion to atmosphere, a downwardly tapering intermediate portion depending from said top portion, the upper end of said intermediate portion being of materially less cross sectional extent than said top portion, and a leg depending from the lower end of said intermediate portion.

4. A grainer of the class described comprising a substantially cylindrical shallow top portion, means for discharging brine under pressure into said top portion substantially tangentially thereof, an inverted frusto-conical intermediate portion depending from said top portion concentric therewith, the upper base of said intermediate portion .being of materially less diameter than said top portion, and a leg depending from the lower base of said intermediate portion.

CLINTON S. ROBISON. 

